混凝土干湿过程及循环制度的研究  

Investigation of the Process and Regime of Drying and Wetting of Concrete

作　　者：庞超明[1,2] 徐剑 王进[1,2] 王伦[1,2,3] 秦鸿根[1,2] 孙伟[1,2] 

机构地区：[1]东南大学材料科学与工程学院,江苏南京211189 [2]东南大学江苏省土木工程材料重点实验室,江苏南京211189 [3]江苏省交通科学研究院有限公司长大桥梁健康检测与诊断交通行业重点实验室,江苏南京211112

出　　处：《建筑材料学报》2013年第2期315-320,共6页Journal of Building Materials

基　　金：国家重点基础研究发展计划(973计划)项目(2009CB623200);国家自然科学基金资助项目(51108077);江苏省自然科学基金资助项目(BK2011612);江苏省崇启大桥建设项目(CQHT-ZG-09002)

摘　　要：将混凝土的干湿循环过程分解为干燥和湿润过程,对其干湿过程中不同深度相对湿度的变化规律、水量蒸发/吸收规律及氯离子对水分传输的影响进行了研究.结果表明:测定混凝土干湿过程中的蒸发/吸水量、相对湿度,可合理制定干湿循环制度,并进行室内试验与现场环境的加速倍率换算;在干湿初期,混凝土失水/吸水速率最大,之后大幅减小;干燥时间决定了混凝土的劣化深度,制定干湿循环制度时宜延长干燥时间,缩短润湿时间;离子的存在不影响混凝土水分的传输方式,但会大大降低其毛细吸附和扩散传输效果.Process of the drying and the wetting for concrete were investigated separately. The change of relative humidity（RH） in different depths of concrete with time during the drying and the wetting was mo nitored. The mass of average evaporation/absorption of water during the drying and the wetting process was also measured, and then the influence of chloride ion on water transportation was considered. The test results show that the drying and wetting regime of concrete can be rationally determined according to the RH and the water evaporation/absorption during the drying and wetting process. The RH and the water e vaporation/absorption obtained in the lab can be transferred to assess the effect of drying and wetting on the insite concrete. The evaporation/absorption rate is the highest during the early drying and the wetting process, and subsequently slows down. The degraded depth Of concrete is determined by the drying process, therefore the drying time shall be long While the wetting time be short. Water transportation mode shall not be influenced by the chloride ion, while the capillary absorption coefficient and diffusion co efficient of concrete markedly decreases.

关 键 词：干湿循环制度 干燥和湿润过程 蒸发 吸水量 相对湿度 

分 类 号：TU528.0[建筑科学—建筑技术科学]